Disable MagicSmoke as it depends on hidden APIs.

Bug: 16031597

RS graphics requires apps to be compiled against v20 or earlier. Building
against internal APIs doesn't allow us to specify LOCAL_SDK_VERSION := 20
or any other valid value.

Change-Id: I6803de8d7022aee65a2c41dc9005740f34581d9d
(cherry picked from commit 7aa068093e814d7a53daa4850dbe5f5c3c16e262)
Merge "Disable MagicSmoke as it depends on hidden APIs."